Chuanyun Fu

• Doctor of Philosophy
• Professor (Associate) at Harbin Institute of Technology

Extreme Value Theory (EVT) models have recently gained increasing popularity for crash risk estimation using traffic conflict data. Extreme value modeling consists of two fundamental approaches: the block maxima approach and the peak-over-threshold approach, each with several variants. However, a comprehensive comparison of these two approaches and...

Autonomous Vehicle (AV) technologies are expected to result in significant safety and mobility benefits to the road system. However, one of the most important issues that autonomous vehicle technology faces is ensuring safe interactions with active road users such as pedestrians who can have unpredictable behavior. Moreover, road user behavior vari...

Crash blackspots significantly impact and, to some extent, determines the entire road network’s safety level. Therefore, it is imperative to identify these blackspots and investigate the contributing factors. This becomes particularly crucial for low-income countries facing financial constraints in implementing road safety measures. Methodologicall...

The use of traffic conflicts in road safety evaluation is gaining considerable popularity as it plays a vital role in developing a proactive safety management strategy and allowing for real-time safety analysis. This study proposes an integrated approach that combines a machine learning (ML) algorithm and a Bayesian spatial Poisson (BSP) model to c...

The economical and rational deployment of automated speed camera is a critical issue for traffic police department to implement speed management efficiently. Based on taxi GPS trajectories collected from Chengdu, 2016, this study optimizes the deployment interval and number of ASCs at the intersections by using K-means clustering and kernel density...

In order to effectively restrict repeated speeding behaviors, this paper first divides the speeding range into three speeding ranges, including low, medium, and high speeding according to the law-enforcement in China. Based on this, we further build the basic framework of a stepwise incremental fine model (SIFM) and a stepped incremental fine model...

Commercial drivers are usually observed with more speeding behaviors than other cohorts. Some of their speeding behaviors occurring under specific conditions may cause more hazards. Hereby, there is a need to verify the hazard caused by different categories of speeding and benefit the anti-speeding countermeasures. This study treats the speeding-re...

Several studies have shown that crash risk is a dynamic quantity that is frequently changing with considerable spatial and temporal variations. Recent advances in safety evaluation techniques such as using extreme value theory (EVT) models provided the opportunity to use traffic conflict data obtained from road user trajectories to estimate real ti...

The use of traffic conflict-based models to estimate crash risk and evaluate the safety of road locations is a popular direction for road safety analysis. However, a challenging issue of traffic conflict-based crash risk modeling is the selection of an appropriate sample size. Reliable conflict-based crash risk models typically require a large samp...

A novel and effective approach to safety management requires evaluating the safety of locations over short time periods (e.g. minutes). Unlike traditional methods that are based on aggregate crash records over a few years, crash proneness in this approach reflects short-time durations and is related to dynamic traffic changes and dangerous driving...

This study proposes an approach for real-time road network safety analysis using autonomous vehicles (AVs) generated data. The approach utilizes a Bayesian hierarchical spatial random parameter extreme value model (BHSRP). The model simultaneously addresses the scarcity and non-stationarity of conflict extremes and unobserved spatial heterogeneity....

Several studies have advocated the use of extreme value theory (EVT) traffic conflict models for real-time crash risk prediction using real-time safety indices such as the risk of crash (RC) and return level of a cycle (RLC). This approach provides a logical framework to estimate crash risk by extrapolating from the observed level (i.e., traffic co...

Using random parameters in combination with extreme value theory (EVT) models has been shown to capture unobserved heterogeneity and improve crash estimation based on traffic conflicts. However, in existing random-parameter EVT models, the predefined distribution means and variances for random parameters are usually constant, which may not capture...

Analyzing speed mean and variance is vital to safety management in urban roadway networks. However, modeling speed mean and variance on structured roads could be influenced by the spatial effects, which are rarely addressed in the existing studies. The inadequacy may lead to biased conclusions when considering vehicle speed as a surrogate safety me...

To efficiently deter the repeated speeders who are frequently fined but continue to commit the violation, this study attempts to investigate the characteristics of the repeated speeding behaviors and propose an increasing block fine modeling approach. Based on the off-site law enforcement data collected from the Deyang City, three speeding ranges (...

Hard-braking constitutes a critical surrogate measure of traffic safety on urban road networks. Efforts aiming to unveil the effects of contributing factors on the occurrence of hard-braking are inadequate. This study extracted the hard-braking event (HBE) and ordinary-braking event (OBE) by GPS trajectories from float cars. The effect of several f...

To accurately estimate the capacity of multi-lane drop-off exclusive roadway, a calculation approach based on effective berths is proposed. First, the study specifically analyzes different layout types of parking and through lanes and introduces the concept of effective berths of drop-off exclusive roadway. A calculation approach of the capacity of...

Exploring the spatial and temporal distribution of traffic violations is vital to road safety management. This study investigated the traffic violations of illegal parking and disobeying the guide lane, which are the most observed in a middle-sized city Luzhou. The temporal distributions between the traffic violations are compared in time of day, d...

Real-time safety analysis and optimization using surrogate safety measures such as traffic conflicts and techniques such extreme value theory (EVT) models is an emerging research topic in the context of proactive traffic safety management. However, the predictive performance and temporal transferability of the existing real-time safety analysis EVT...

The study presents spatial analysis of traffic violations in Luzhou city, China. Three metrics of spatial point pattern, namely intensity, spatial correlation, and spacing, are evaluated using (i) kernel density and quadrant count; (ii) K and L functions; and (iii) nearest neighbor and empty-space distance methods, respectively. The results show th...

The freeway accident detection and classification have attracted much attention of researchers in the past decades. With the popularity of Global Navigation Satellite System (GNSS) on mobile phones and onboard equipment, increasing amounts of real-time vehicle trajectory data can be obtained more and more easily, which provides a potential way to u...

Partial taxi speeders are observed with both high speeding frequency and severity (range). They thereby can be viewed as aggressive speeders whose behaviors may result in more hazards than others. Among the factors contributing to taxi speeding, the operational factors are proven to be deterministic. However, previous studies mainly investigate the...

Most existing Extreme Value Theory (EVT) models were developed based on the total number of conflicts or a single type of traffic conflict to estimate the corresponding frequency of crashes. Using the total number of conflicts to estimate the total number of crashes may make it difficult to diagnose safety problems as counter-measures are usually relate...

The use of Extreme Value Theory (EVT) models for traffic conflict-based crash estimation is becoming increasingly popular with considerable recent advances achieved. The latest advances include developing EVT models that combine several conflict indicators and the use of data from several sites to increase the sample size of conflict extremes. Neve...

There is an increased interest in the use of traffic conflicts as a surrogate safety measure and several traffic conflict indicators have been developed. One of these indicators is the deceleration rate to avoid a crash (DRAC). Generally, the greater the DRAC value, the higher the crash risk and a crash would occur when the DRAC exceeds the maximum...

The use of non-motorized vehicles in urban city has improved the convenience of short-distance travel and reduced traffic pollution. However, the overtaking behaviour of non-motorized vehicles impacts traffic safety and efficiency significantly. The objective of this study is to model the durations of overtaking behaviour in the non-motorized vehic...

Recent studies have demonstrated that single conflict indicators represent only a fractional aspect of the severity of a traffic interaction. As such, integrating several conflict indicators in a unified model can improve conflict-based crash estimation. This study develops a multivariate Bayesian hierarchical Gaussian copula modeling approach, whi...

Speeding behavior, especially serious speeding, is more common in taxi driver than other driving population due to their high exposure under traffic environment, which increases the risk of being involved in crashes. In order to prevent the taxi and other road users from speed-related crash, previous studies have revealed contributors of demographi...

Deaths and injuries resulted from road traffic crashes remain a serious problem globally, and current trends suggest that this will continue to be the case in the foreseeable future mainly in developing countries. Among diverse cause of traffic safety challenges, traffic violation has been considered as one of the noticeable contributing factors. T...

Recent studies have developed univariate and bivariate Bayesian hierarchical extreme value models to improve traffic conflict-based crash estimation through addressing the issues of non-stationarity of conflict extremes and individual conflict indicators representing only partial severity aspects of a traffic event. Although the use of bivariate mo...

Urban traffic crashes may lead to only a few casualties, but may generate severe negative impacts on the surrounding traffic, such as evidently increasing traveling delay and non-essential fuel consumption of third parties (i.e., vehicles not involved in the crash). Such detrimental consequences of urban traffic crashes are usually ignored by the t...

Rheumatoid arthritis (RA) is the most common inflammatory disease, which currently lacks effective treatment. Here, we discovered the Regulator of G Protein Signaling 12 (RGS12) plays a key role in regulating inflammation. Transcriptional and protein analysis revealed that RGS12 was upregulated in human and mouse RA macrophages. Deletion of RGS12 i...

The quality of vehicular collision data is crucial for studying the relationship between injury severity and collision factors. Misclassified injury severity data in the crash dataset, however, may cause inaccurate parameter estimates and consequently lead to biased conclusions and poorly designed countermeasures. This is particularly true for imba...

To effectively reduce traffic violations that often cause severe crashes at signalized intersections, exploring their contributing factors seems hugely urgent and essential. This study attempted to investigate the influence factors of wrong-way driving (WWD), red-light-running (RLR), violating traffic markings (VTM), and driving in the inaccurate o...

This study introduced the anti-speeding effectiveness of ISA as well as acceptance from 2010 to 2019, which followed the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. Based on the selection criteria, four key items were searched from six databases and 26 studies were selected. It is reported that research i...

ELife digest Human bodies change with age, and the skeleton is among the parts of the body most visibly affected. This is because bone tissue tends to decrease as the skeleton gets older. For example, people often get shorter as they get older, mostly because they lose bone mass in areas of the skeleton that support posture. Severe bone loss can al...

From temporal and locational perspectives, the influence factors of traffic violations for taxi drivers remain unclear. Hence, this study attempts to investigate the effects of temporal and locational factors on traffic violations of taxi drivers using descriptive statistics and Chi-square test based on data extracted from the off-site enforcement...

Red-light running is one of the major causes for traffic crashes at signalized intersection. In addition to traffic engineering and management measures, enforcement countermeasures are employed to encourage drivers to comply with traffic signal through the threat of penalty points and fine. However, the fine associated with red-light running is fix...

Bone homeostasis is intimately relied on the balance between osteoblasts (OBs) and osteoclasts (OCs). Our previous studies have revealed that regulator of G protein signaling protein 12 (Rgs12), the largest protein in the Rgs super family, is essential for osteoclastogenesis from hematopoietic cells and OC precursors. However, how Rgs12 regulates O...

This study attempts to assess the intervention effectiveness of a new traffic regulation on red-light running (RLR) based on RLR records collected in Harbin, China. Descriptive statistics and a chi-square test were applied to investigate the variation patterns regarding the number of RLR and RLR vehicles by vehicle type and RLR level before and aft...

In order to explore the impacts of various factors on air route connection, a probability model is constructed to simulate the Chinese airline network (CAN) in 2010, and the influences of tertiary industry output, degree and the spatial distance between two navigable cities on the analog results are discussed. Our research shows that, the opening o...

Countdown timers display the time left on the current signal, which makes drivers be more ready to react to the phase change. However, previous related studies have rarely explored the effects of countdown timer on driver's brake perception-reaction time (BPRT) to yellow light. The goal of this study was therefore to characterize and model driver's...

A few studies have proposed the notion of deploying automated speed photo enforcement at signalized intersections to deter drivers from intentionally running yellow lights. An appropriate speed limit is the critical determinant for automated speed photo enforcement, but this has rarely been explored. Hence, this study attempts to investigate the sp...

An amperometric biosensor, constructed through a specific design featuring a bienzyme doped sol–gel and an Os-complex mediator layer, capped with electropolymerized polyphenol semipermeable membranes, is presented for lactate quantification in saliva. The new enzymatic biosensor exhibits impressive linear and low response times in a phosphate buffe...

To investigate the available evidence referring to the effectiveness of digital countdown timer (DCT) to improve the safety and operational efficiency of signalized intersection. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines. Relevant literature wa...

Highly sensitive detection of hepatitis C virus (HCV) in serum is a key method for diagnosing and classifying the extent of HCV infection. In this study, a p-phenol derivative, 4-(1,2,4-triazol-1-yl)phenol (4-TRP), was employed as an efficient enhancer of the luminol-hydrogen peroxide (H2 O2 )-horseradish peroxidase (HRP) chemiluminescence (CL) sys...

It is well known that intersections are the most hazardous locations; however, only little is known about driver injury severity in intersection crashes. Hence, the main goal of this study was to further examine the different factors contributing to driver injury severity involved in fatal crashes at intersections. Data used for the present analysi...

The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic ad...

The yellow light dilemma zone is widely known as an area on the high-speed intersection approach, where vehicles neither safely stop before the stop line nor proceed through the intersection during amber interval. Within such an area, a vehicle might be involved in a right-angle crash or rear-end collision. This issue has been extensively discussed...

Many studies suggest that more crashes occur due to mixed traffic flow at unsignalized intersections. However, very little is known about the injury severity of these crashes. The objective of this study is therefore to investigate how contributory factors affect crash injury severity at unsignalized intersections. The dataset used for this analysi...

Driving violation has been identified as one of the prominent contributing factors involved in crashes occurring at intersections. However, very little literature has studied the influence of contributory factors on driving violation. The goal of the present study was to analyze the effect of contributory factors on traffic sign and signals (TSS) v...

Drink-driving has a significant impact on road traffic safety. Based on the choice of driver’s physiological and eye movement characteristics indicators, this study compared driver's skin electricity change characteristics was compared under different alcohol intake, heart rate scatter diagram was used to establish the Poincare section, and driver’...

The progress of vehicle collision can be broken into three stages: pre-collision, collision and post-collision. Although the direct collision lasts very little time, it is one of the most important stages of the whole process. On the basis of Momentum Conservation, Energy Conservation and improved Coefficient of Elastic Recovery, using Newtonian Me...

This paper, base on analyzing visibility under different conditions, analyzed the influence to driving visibility in ice snow environment, and studied driver's vision and psychology & physiology in the same environment through experimentation. So studying on driver's legibility effectiveness of traffic signs under the ice and snow condition and est...

According to statistical data, risky merging driving behavior has taken adverse impact on traffic safety, and it widely exists in the ramp connecting section of urban expressway. Risky merging driving behavior can be divided into three types considering the difference in merging speed of vehicle, and the statistical characteristics of risky merging...

In order to evaluate traffic operation safety of urban ice and snow road objectively, ice and snow pavement friction coefficient, visibility, following distance and snow-accumulated depth are chosen as evaluation indexes and their criteria are established. Evaluation indexes are weighted by using the improved entropy weight coefficient method, and...

Many unsignalized roundabouts with multi-entry-lane and multi-circulating-lane are still used in urban road of China, where the situation of traffic flow running is very complicated, and the calculation of traffic capacity of unsigalized roundabout needs further research. The fact that most entry vehicles only cross outside two circulating lanes is...

The influence area of urban road traffic accident is studied in order to take effective measures for reducing the impact. On the basis of analyzing that traffic accident impacts on road network, the accident effect includes two processes of vehicle queue formation and queue dissipation, the relationship of them belongs to inclusion relation on the...

Some factors affect the driving behavior seriously, for example driving visibility, velocity, headway, driver’s vision and psychology&physiology etc. This paper, base on analyzing visibility under different conditions, analyzed the influence to driving visibility in ice & snow environment, and studied driver’s vision and psychology&physiology in th...